Designing Device Circuits

1. Select the capacitors to suit installation and operating conditions,

and use the capacitors to meet the performance limits prescribed in

this catalog or the product specifications.

2. Polarity

Aluminum Electrolytic Capacitors are polarized.

Apply neither reverse voltage nor AC voltage to polarized capacitors.

Using reversed polarity causes a short circuit or venting. Before use,

refer to the catalog, product specifications or capacitor body to identify

the polarity marking. (The shape of rubber seal does not represent the

directional rule for polarity.) Use a bi-polar type of non-solid aluminum

electrolytic capacitor for a circuit where the polarity is occasionally

reversed. However, note that even a bi-polar aluminum electrolytic

capacitor must not be used for AC voltage applications.

3. Operating voltage

Do not apply a DC voltage which exceeds the full rated voltage. The

peak voltage of a superimposed AC voltage (ripple voltage) on the DC

voltage must not exceed the full rated voltage.

A surge voltage value, which exceeds the full rated voltage, is prescribed

in the catalogs, but it is a restricted condition, for especially short periods

of time.

4. Ripple current

The rated ripple current has been specified at a certain ripple frequency.

The rated ripple current at several frequencies must be calculated by

multiplying the rated ripple current at the original frequency using the

frequency multipliers for each product series.

5. Category temperature

The use of a capacitor outside the maximum rated category temperature

will considerably shorten the life or cause the capacitor to vent.

The relation between the lifetime of aluminum electrolytic capacitors and

ambient temperature follows Arrhenius' rule that the lifetime is

approximately halved with each 10°C rise in ambient temperature.

6. Life expectancy

Select the capacitors to meet the service life of a device.

7. Charge and discharge

Do not use capacitors in circuits where heavy charge and discharge

cycles are frequently repeated. Frequent and sharp heavy discharging

cycles will result in decreasing capacitance and damage to the capacitors

due to generated heat. Specified capacitors can be designed to enduring

such a condition. Rapid charging/discharging may be repeated in a circuit

where the ripple voltage at the two terminals of the aluminum electrolytic

capacitor fluctuates greatly. If the variation range of voltage exceeds

70Vp-p, please consult us.

8. Failure modes of capacitors

Non-solid aluminum electrolytic capacitors, in general, have a lifetime

which ends in an open circuit, the period is dependent upon temperature.

Consequently, lifetime of capacitors can be extended by reducing the

ambient temperature and/or ripple current.

9. Insulation

a) Electrically isolate the following parts of the capacitor from the negative pole

terminals, positive terminals and circuit traces.

• Cases for non-solid aluminum electrolytic capacitors.

• Dummy terminals for non-solid aluminum electrolytic capacitors,

This is designed for installation stability.

b) The casing of the capacitor is not guaranteed to be an insulator (except

 for screw type). For applications requiring an insulating outer layer

 sleeve, custom designed capacitors are recommended.

10. Conditions

Do not use/exposed capacitors under the following conditions.

a) Oil, water, brine. Avoid storing in damp places.

b) Direct sunlight.

c) Toxic gases such as hydrogen sulfide, sulfurous acid, nitrous acid, chlorine or its compounds, and ammonium.

d) Ozone, UV or radiation.

e) Severe vibration or mechanical shock conditions beyond the limit

 specified in the catalog or product specification.

11. Installation

a) Electrolytic paper and electrolytic conductive electrolyte

 Non-solid aluminum electrolytic capacitors are flammable. leakage

 Electrolyte on printed circuit boards can gradually corrode copper

traces, which may cause smoking or burning through a short circuit

copper traces.

 Verify the following points when designing the PC board.

• Provide proper hole spacing on PC board to match

 Terminal spacing of capacitors.

• Leave the following open space above the vent so that the vent can

Proper operation.

 Case Diameter Clearance

 Ø6.3 to Ø16mm minimum 2mm

 Ø18 to Ø35mm minimum 3mm

 Ø40mm or more 5mm minimum

• Do not place any wires or copper traces on the device's vents.

capacitor.

• Installing a capacitor with a vent facing the PC board requires a

There are proper ventilation holes on the PC board.

• Do not run any copper traces under the capacitor seal.

The traces must go through 1 or 2mm to one side of the capacitor.

• Avoid placing any hot objects near

capacitors, even on the reverse side of the PC board.

• Do not pass anything through holes or under capacitors.

• When designing double-sided printed circuit boards, do not place any copper

Trace the sealed side of the next capacitor.

b) Do not install the terminal side of the screw-mounted capacitor downward.

If the screw terminal capacitor is mounted on its side, make sure

Positive is higher than negative.

 Do not fasten the terminal screws and mounting clips to the